In January, 2004, the United States successfully launched “Spirit”, a Mars Exploration Rover, _____ a new milestone in the history of mankind.
Below ____ an article about advertisements ____ by a student for her English project.
_____ an ad does not lie, it does not mean it is altogether innocent.
She set off at 9 a.m. and ____ the airport an hour later.
If ____ in, viruses can result in illness or even death.
By the 1920s, Howard Carter ____ an explorer.